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How Long Should a Mechanic Keep Records? IRS, Payroll, and State Repair Rules

Updated 2026-10-17. Sources are listed at the end.

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This is general information, not legal or tax advice. Rules vary by state and change often. Confirm with the official source linked in each section, or with a licensed attorney, CPA or insurance agent, before you act.

Repair businesses generate a lot of paper: estimates, signed authorizations, invoices, parts receipts, mileage logs, payroll records. Different agencies require you to keep different pieces for different lengths of time. Here are the official periods, and a plan that covers all of them without keeping everything forever.

Tax records: what the IRS says

From the IRS page How long should I keep records? (IRS):

SituationKeep records for
Normal case3 years from filing
You file a claim for credit or refund after filing3 years from filing or 2 years from paying the tax, whichever is later
Bad debt deduction or loss from worthless securities7 years
You failed to report income over 25% of the gross income shown6 years
No return filed, or a fraudulent returnIndefinitely
Employment tax recordsAt least 4 years after the tax is due or paid, whichever is later

The IRS also says to keep property records (tools, equipment, the van) until the limitations period expires for the year you dispose of the property. You need them to figure depreciation and gain or loss. A scan tool bought in 2026 and sold in 2031 means keeping the receipt until about 2035.

Mileage logs support your vehicle deduction, so keep them with that year’s return. See the 2026 mileage deduction guide and tool & van deductions.

Bad debts matter for mechanics. If you write off an unpaid invoice as a bad debt, the IRS period is 7 years. Keep that job’s estimate, invoice and collection attempts. See when a customer won’t pay.

Repair records: state rules

State / agencyWhatHow long
California (BAR)Estimates, invoices and other repair records, open to BAR inspectionAt least 3 years
Florida (FDACS)Business records under the Motor Vehicle Repair Act1 year
California (CARB)Aftermarket catalytic converter installation records4 years (per CARB’s procedures)

Sources: BAR, Write It Right; FDACS, Motor Vehicle Repair; CARB evaluation procedures, PDF.

California also requires a unique identifier linking every record from one job, and BAR reminds shops that if records are stored electronically, documents with a customer’s signature must be scanned. Details in estimate & invoice requirements and catalytic converter rules.

Other states have their own rules. Check your state’s repair-registration agency (see license requirements).

A simple retention plan

  1. Job files (estimate, authorization, change orders, invoice, photos): keep at least 4 years. That covers California’s 3 years and CARB’s 4, with margin. If you take bad-debt write-offs, keep those job files 7 years.
  2. Tax returns and supporting records: at least 3 years after filing. Many owners keep them 7 years to cover the longer IRS periods.
  3. Payroll records, if you have employees: at least 4 years after the tax is due or paid. See hiring your first technician.
  4. Asset records: until about 3 years after the tax year you sell or scrap the item.
  5. Warranty records: at least as long as your longest warranty term. See parts & labor warranty policy.

Go digital. Shop management software stores estimates, signatures and invoices by job automatically, which gives you the unique identifier California wants. Export a backup once a year. If you use the free estimate & invoice generator, save each PDF in a folder by year and job number.

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Sources